August dauber



(No Model.)

.A. DAUBBR. rnocnss OF MAKING 130m 4 superfi Patented Aug 1, 1893.

Witnesses:

UNHTED ST ES PATENT Or fice,

AUGUST DAUBER, or BOOHUM, GERMANY.

PROCESS OF MAKING IRON.

SPECIIEIQATIOII forming part of Letters Patent No. 502,482, dated August1,1893.

Application filed June 18, 1890. Serial No. 355,889. (No specimens.)Patented in Germany September 19,1889.No.l)4,005; in

France October 4,1889,N0,201,107: in Luxemburg April 25,1890, No. 1,281,and in Belgium April 25, 1890,110- 67,709-

To all whom it may concern:

Be it known that I, AUGUST DAUBER, a subject of His Majesty the Emperorof Germany, residing at Bochum, in the Province of Westphalia, Germany,have inventedcertain new and useful Improvements in Processes of MakingIron of any Quality, Pig-Iron, WVrought- Iron, Cast-Steel, and RoughSteel, (for which I have obtained patents in Germany, provisional No.D4,005, dated September 19, 1889; in France, No. 201,107, dated October4,, 1889; in Luxemburg, No. 1,281, dated April25, 1890, and in Belgium,No. 67,709, dated April 25, 1890;) and I do hereby declare that thefollowingis a full, clear, and exact description of the invention, whichwill enable others skilled in the art to which it appertains to make anduse the same.

It is a well known fact that in burning carbon in gaseous state incombination with oxygen over one hundred per cent. of calories or unitsof heat more are obtained than when the combination of the oxygen withthe carbon in a solid state takes place. For this reason many trialshave been made of late years to use gaseous combustibles instead of suchin a solid state for heating purposes of any sort. If anywhere, this,extraordinary gain must prove profitable in the iron industry, thelargest consumer of coal, provided that it will be possible to introducethe easily obtainable gas in place of coal and coke into the highfurnace in a practicable manner and at the proper place. Combined withthis gain obtained by using gaseous fuel there is another, which is theabsolute consequence of the use of gaseous fuel in blast and similarfurnaces, namely the space gained in a furnace which otherwise isoccupied by the coal or coke and which now will be free. All that spaceformally occupied by the coal or coke, about one-third of the wholevolume of a furnace, is now available for ores and lime stone or flux.The production of a blast and similar furnace worked by gaseous fuel ascompared with one where coal or coke or other solid fuel is used,therefore must be larger in proportion to the space gained in the firstcase, ora furnace of the first class may be built so much smaller fromthe beginning to give out'the same quantity of iron as in the othercase, and the first costs of building will therefore be reducedconsiderably also.

The object of my invention is to realize the gains named bythe use ofgaseous fuel or carbon in a fluid or pulverized state which is blowninto the furnace at certain stages in such combinations with or withoutheated air and superheated steam and .in such proportions as willcorrespond to the reaction going on in the furnace at that stage in thatplace and at that time; injector like tuyeres being used for regulatingthe quantities of each gas so as to obtain the proper mixture required.The success will be assured if the zones of preparatiomof reduction,o fcarbonization, of melting and of maturation so created will be placed atthe rightplace in the furnace and if the reactions taking place thereare caused at the proper time andin the proper proportions to the fuelblown into the furnace. In order to secure this result I introduce thegases into the furnace at those places in such a state that answers thereactions having to take place there by means of adjustable injectorlike combined tuyercs. The gases used, superheated steam and hot air,each for itself or in combination with the others in adj ustableproportions are produced in separate generators so .as to have themalways ready in sufficient quantities and in proper condition. 1

For the sake of following the process going on in a furnace designed tocorrespond to my method of iron making let us suppose the furnace be atwork. The starting having to be done as usual with solid fuel and onlywhen the work is going on in regular order, the new method is beingintroduced gradually by reducing by degrees and replacing the solidfuelcoal or coke-by at first gradual and then continuous charges ofgases and carbon which are blown into the furnace. At the bottom of thezone of preparation or as near as this place can be fixed, I arrange arow of tuyeres by means of which superheated steam or heated air isblown in, in order to dry and roast the charges, ore and flux, and tofree them from the humidity contained therein and from other volatilematerials and to prepare them so for the reception of oxide of carbonand to make them loose and open. In

the zone of carbonization I arrange a similar row of tuyeres, the objectof which is to introduce carbon and to mix it with the ores so as toprepare them for the melting process. The blowing in of carbon may bedone by the use of gaseous carbon or in a fluid-or in a pulverizedstate, or'any of these combined with the other. In the melting zone Iarrange tuyeres by means of which I blow into the furnace a mixture ofheated gas and air to which superheated steam may be added, in order toproduce the high temperature which is necessary to reduce into a fluidstate also the earthen material and so to separate completely the ironfrom the slag and cinders in consequence and according to the differenceof their specific weights.

In order to be able to vary the composition of the produce or itsquality in the hearth at will so as to receive spiegeleisen, forinstance, with a high percentage of carbon down to mottled ironcontaining but traces of carbon, as Well as steel of any sort, I hereprovide a zone of maturation by arranging a similar row of tuyeresthrough which Iblow into the furnace at this place a mixture of gas andsuperheated steam and hot air, which may be varied as desired so as toreduce the carbon in the iron to the required degree.

It may be added here that my method differs materially from that usedfor ashort time in England and America by Glay Bull who blew the gas andair into the furnace each at opposite sides and only at the bottom ofthe furnace, for which reason his furnaces after a short period wereblown cold.

The furnace used with my process is shown on the annexed drawings inwhich- Figure l is a vertical section of the furnace with a movablehearth. Fig. 2 is a similar section at right angles to Fig. l, the leftside showing a fixed hearth or crucible, the left half having a movablecrucible. Fig. 3 is a cross section along line II of Fig. 1. Fig. 4 is across section along line II-II. Fig. 5 shows a section on an enlargedscale of the combination tuyere used.

The blast furnace A is in its main part of ordinary construction. At thehead of the same it is provided with the hood or cap B with the pipes OO branching off for leading away the gases, a bell cover D serving forclosing the top as in ordinary furnaces. The upper part of the furnaceis mounted on six pillars E and supported by a strong iron plate F. Thehearth may be fixed as shown on the left side of Fig. 2 or it may bemovable on Wheels as shown in Fig. 1 and on the right side of Fig. 2.This is however immaterial and may be made in the one way or the other,as it is not peculiar to my process or to the furnace. So far asdescribed the furnace is not distinguished from ordinary blast furnaces.But I differ from ordinary constructions in the arrangement of tuyeres.I arrange special tuyeres in the zones of reduction of carbonization andin the melting zones, G, H and I respectively by means of which Iblowinto the furnace the necessary gases as stated in describing theprocess above. The mixture of these gases or the proportions in whichthey are mixed vary according to the nature of the ores and flux used,and they also depend upon the process going on in the furnace. Themelter regulates this process by altering the mixtures so that a regulargoing will be maintained. Below the melting zone I also have a row ofcombined tuyeres K and 1 thus form what I call the zone of maturation orthe crucible, because it is here, where I complete the process byreducing the contents of carbon, so as to obtain either wrought iron,steel or cast iron in its various shades and according to the quality orthe nature of the product desired. I vary the mixture of the gas bymeans of the combined tuyeres. Fig. 5 shows the arrangement of such acombined tuyere.

L is the central tube for hot air. By M superheated steam may be addedand by N the carbon gas is introduced and the tube 0 serves for blowingin carbon ina pulverized orfluid state. Every one of these tubes maybeshut off by valves P, P P or P respectively. They are arrangedconcentrically to each other and they all blow into a common tube Rwhich leads into the furnace.

Having now particularly described the nature of my invention, what Iclaim, and desire to secure by LettersPatent, is-

The process of reducingiron which consists in charging into a blastfurnace, a mixture of ore and flux, without carbon, and introducing intothe furnace at the zone of preparation a heated gas containing oxygen,at the zone of carburization, carbon superheated steam and heated air;at the zone of melting, a heated combustible gas, superheated steam, airand carbon, and into the crucible containing molten metal a mixture ofgas, superheated steam and air.

AUG. DAUBER.

Witnesses:

OHs. KRUEGER, RUDOLPH FRIOKE.

